Human mobility entails execution of several tasks including path planning, navigation, and obstacle avoidance. Visually impaired people cannot accurately assess the surrounding environment. Seeing-eye dogs and white canes are widely used for the purpose of guidance and environment sensing. The former, however, has costly and often prohibitive training requirements, while the latter can only provide cues about ones immediate surroundings.
Traditional systems for navigating within a building are generally costly or ineffective. For example, the installation and operating costs associated with an installed base of radio frequency markers within a building are substantial barriers not readily overcome. In addition, poor reception of radio frequency navigation signals within a building, such as that used by satellite-based navigation systems (for example, global positioning systems), precludes widespread acceptance.